Sanding drum



y 20, 1941- w. H. VAN ZQMEREN 2,242,377

SANDING DRUM Filed Aug. 10, 1939 2 Sheets-Sheet 1 INVENTOR.

Patented May 20,1941

' STAT This invention relates to improvements in sanding drums.

The main objects of my invention are:

First, to provide an improved sanding drum to which thesanding orpolishing web may be .5'

applied without removing the drum from the arbor.

Second, to provide a sanding drum having this advantage in which the webis efiectively held, the structure is strong and durable and at the sametime light in weight and very economical in its parts.

Further objects relating to details and economies of my invention willdefinitely appear from the description to follow. The invention is de- 1fined in the claims.

A structure embodying the features of my invention is illustrated in theaccompanying drawings, wherein:

Fig. 1 is a perspective view illustrating the 529 drum of my inventionremoved from the arbor of a sanding machine or device and with a sandingor polishing weboperatively secured thereon.

Fig. 2 is a fragmentary view in section on a line corresponding to line2.2 of Fig. 3, illus- .1 1 trating details of the construction.

Fig. 3 is a view in front elevation illustrating the manner ofmanipulating the drum of my invention to renew or replace the abrasiveweb thereon.

Fig. 4 is a view in front elevation illustrating a modified embodimentof my invention, the manner of manipulating the same being illustratedin dotted lines.

Fig. 5 is a fragmentary detail View in section on line 55 of Fig. 4.

Fig. 6 is a view in section similar to Fig. 2, illustrating modifiedmeans for holding the coacting drum elements together in operativeposi-, tion.

Fig. 7 is a fragmentary view illustrating the manner of manipulating themeans of Fig. 6 in removing the drum from the arbor or for replacing theabrasive web thereof.

Fig. 8 is a view similar to Fig. 3, still further illustrating themanner of manipulating the modified embodiment of Figs. 6 and '7 toreplace the abrasive web.

Fig. 9 is a view similar to Fig. 6, illustrating a still furthermodified form of securing means for the coacting drum elements.

Fig. 10 is a fragmentary perspective view of an elongated drum of whichthe drum assemblies of my invention may form a part, being partiallybroken away to illustrate the interior of the drum 55 and the manner inwhich it is made up from a plurality of drum assemblies.

In the drawings, the reference numeral l generally indicates the drumassembly of my inven-'- tion, which consists of a central hub member 2adapted to be removably secured on the-arbor 3-of a sanding or polishingmachine or device, as illustrated in Fig. 2, a washer sand nut 5threadedly received by the arbor being employed 'for this purpose. Thehub member 2 preferably has an integral, annular, radially extending webor flange 6 adapted to receive an internal annular channel 1 carried bythe drum 8 of the assembly.

This drum, in the preferred embodiment, is

made up of pairs of'sheet' metal stampings in the form of centrallyaperturedsemi-circular disks 9 having parallel oppositely disposed axialflanges 1-0. The radially extending webs ll of the semi-circular disks 9are'each offset axially in the direction of its corresponding flange sothat when the two thereof are united as by spot welding I2 with therespective flanges extending in opposite directions,- a semi-circulardrum element IZI is formed, having the inwardly opening semi-circularchannel 1.

A pair of the drum elements l2! made up as described above are hingedlyconnected by a hinge which is generally designated l3 and one of thesehingedly connected semi-circular drum elements is mounted'on the web 6of the hub member 2 with the channel 1 receiving the latter web orflange and rigidly secured thereto as by rivets I l. The other of thewelded disk elements has its webs H apertured and struck out in an axialdirection at the channel 1 to provide axially alined holes'or aperturesl5, 86 to receive a conicalheaded screw ll, which screw is threadedlyreceived in hole l5. The material adjacent aperture I6 is flared outwardto provide a conical seat 16] to receive the screw and the web or flange6 of the hub member is'provided with a chordlike slot l8 terminating ina conically counterbored aperture IE! to likewise receive the conicalhead of the screw ll, so that when the semicircular drum elements .lZlare brought together and the-screw ll istightened, the said diskelements are held in operative position by the engagement of the head ofthe screw in'this counterbored aperture. The shank of the screw'isreceivable in the slot I8 in manipulating the parts and upon tighteningthe head thereof is engageable with the counterbored opening to lock theparts against outward separation. The

thus associated flanges l0 coact to provide the 'edly receive a lockingring supporting surface of the drum upon which is mounted a resilientbacking pad 26. Each of the semi-circular drum elements carries a pin orpenetrating point 2| engageable with an end of the abrasive web 22 toanchor the same in position on the pad. In use, the semi-circular diskelements are separated as illustrated in Fig. 3, and to replace a wornabrasive web, the ends of the new web are secured on the points 2|, thedrum elements l2 being then brought'together and locked by tighteningscrew l1 to thereby tension the web.

To protect the ends of the resilient cushion 20, I provide the segmentswith angled guard members 34 which overlie the ends of the cushionandsustain the pull of the band at this point. The purpose of theseguardsis to prevent the of Figs. 1, 2, and 3, to maintain the thuslocked up assembly on the arbor.

As illustrated in Figs. '7 and 8, when it is desired to replace thesanding web 22, this may be accomplished without removing the assemblyband from distorting the cushions at this point, which would result inan objectionable depression in the surface of the wheel or drum. Theseguard elements also have the further advantage of counterbalancingthehinge l3.

In Figs. 4 and 5, I illustrate a modified embodiment of my invention,wherein the semicircular disk or drum elements 23 are die cast and areprovided with the flanged coacting semi-"circular drum surfaces 24 andradial stiffening flanges 25. One. of these die cast elements includesan integral hub portion 26 receivable on the arbor 3" and the otherthereof has a complementary portion 21 coactingwith the hub portion 26which is cut away to receive it and provide an equal distribution of theweight of the device. The hub carrying element is also provided with aslotted tongue 28 projecting from its side, this tongue being 'ofi'setslightly axially at 29 toaccommodate the web of the other disk element.The slot in'tongue 23 terminates in a conicallycounterbored opening 30'therein to receive the conical headed screw 3| which is threaded in theelementwhich overlaps the tongue in a manner similar to that discussedin the embodiment of Figs. 1 to 3. In the embodiment of Figs. 4 and 5,the bosses 32 drum elements are formed in the casting operation anddrilled to receive a hinge pin 33. Y

for the hinge pivots pivotally connecting the from the arbor by'merelybacking off the locking ring 36, as illustrated in Fig. 7, this ringtelescoping over the smaller securing nut 5. With the parts in thisposition, the drum elements or semi-circular disks 9 may be swung apartto position illustrated in Fig. 8 for replacement of the abrasive web.Of course, if it is desired toremove the assembly from the arbor, allthat is necessary is to back off the securing nut 5.

In Fig.- 9, I illustrate a still further modification of the aforesaidaxial securing means for the assembly in the form of a special lockingnut 38 internally threaded to threadedly engage directly on the arborand provided with an axial recess 39 receiving hub 2, which recess has atapered or conical annular side wall wedgingly engageable with theannular lips 34 in the manner of the locking ring 36 in Fig. 6. Thisembodiment eliminates one of the parts required in'that of Fig. 6. Theoperations of releasing the drum elements for replacement of theabrasive web and for removing the drum from the arbor are obvious andsimilar to those described in connection with Figs. 7 and 8.

In the embodiment of Fig. 1, the rivets [4 are employed to secure thefixed semi-circular drum element or disk 9 to the hub web 6, while inFig. 6 this is accomplished by a welding operation at the point 4|.Within the scope of my invention, these expedients are equivalents and.furthermore, the connection of the sheet metal channel II to the hub maybe made by remov- The manner of using the assembly of Figs. 4

and 5 is similar in all respects to that of Figs. 1 to 32nd in each ofthe embodiments the coacting 'disk or drum elements are firmly held inoperative relation by the coaction of the conical or large headed screwwith the conically 'formed or counterbored screw receiving recess. Thesanding web or moved without removing the drum from the arbor. In sometypes of sanding machines, this is a very great advantage. A furtheradvantage of the structure is that theweb or band is readily applied sothat it is held in tightly embracing B0} relation with the drum. Y r InFigs. 6, 7, and 8, I illustrate furthermodified means for securing .thedrum elements together in operative position, these drum ele- 'mentsbeing generally similar to and constructed in the same manner as thoseillustrated in Figs. 1, 2, and 3, save for the fact that theradiallyextending sheet metal webs II are pro- 'vided at their inner peripheryadjacent the hub member Zwith annular out-turned lips 34 adapted", toengage the vhub 2 in operative position. The hub-is provided with anintegral externally threaded axial extension 35 adapted to thread- 36having a tapered opening 31 engageable over the annular lips band may bequickly re- 5) able means such as screws ii desired in order to enable agiven channel to be associated with hubs having arbor receiving openingsof different size. e

In any of the embodiments illustrated in Figs. 1 to 3 and 6 to 9, theuse of a hub member 2 having a radial web 6 receivable in thesimilarly-formed semi-circular channels I of the drum elements providesa structurewhich is easy to a semble. which efiectively maintains theaxial alinement of'the two pivoted sheet metal drum elements and which.moreover. enables these elements to be quickly applied to the arbor ofthe sanding machine with a minimum of difficulty.

In-some instances, it may be desirable to furnish a sanding drum ofgreater axial dimension than those illustrated in Figs. 1 to 9 of thepresent application. In such case. it is possible to produce a unitofgreater axial length by connecting a pair of axially alined drumassemblies in' accordance with my invention by means of an elongatedmetal bridging the periphery of the assemblies and secured thereto byspot welding at 43. The sheet '42 is secured to the assemblies l in amanner to 34 ments of the assembly in a manner which will be strip 42wrapped around and,

apparent and when operatively secured or locked on the machine arbor bythe means described above constitutes the outermost peripheral web of arelatively elongated drum and supports the elongated resilient backingblanket 44 receiving 'the abrasive web 45. This unit has ampleresistance to deflection for ordinary sanding and is built up fromassemblies in accordance with my invention at small additional cost.

I have illustrated and described my improve ments in embodiments whichare very practical. I have not attempted to illustrate or describe otherembodiments or adaptations as it is believed this disclosure will enablethose skilled in the art to embody or adapt my improvements as may bedesired.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent is:

1. A sanding drum comprising a pair of semicircular drum elementspivotally connected at one side thereof and adapted when broughttogether to constitute a circular drum for receiving an abrasive web,comprising a hub member having a radially extending annular flange, saidelements each having an inwardly opening semiannular channel receivingand engaging said flange, means for rigidly securing one of saidelements to the hub member with the channel thereof receiving said hubflange, said flange having a chord-like slot therein terminating in acounterbored axially extending hole, the other of said elements havingan axially extending hole adapted to be alined with said first namedhole when the channel thereof is in operative receiving relation to saidflange, and a headed screw carried by the last named element and movablein said slot, the shank of said screw extending through said holes inthe operative position of the elements and the head of the screwengaging the counterbore of said flange hole to secure said screwcarrying element from separating movement relative to the flange.

2. A sanding drum comprising a pair of segmental pivotally connecteddrum elements adapted when brought together to constitute a circulardrum for receiving an abrasive web, comprising a hub member having aradially extending annular flange, said elements each having an inwardlyopening channel receiving and engaging said flange, means for rigidlysecuring one of said elements to the hub member with the channel thereofreceiving said hub flange, said flange having a chord-like slot thereinterminating in a counterbored axially extending hole, the other of saidelements having an axially extending hole adapted to be alined with saidfirst named hole when the channel thereof is in operative receivingrelation to said flange, and a headed screw carried by the last namedelement and movable in said slot, the shank of said screw extendingthrough said holes in the operative position of the elements and thehead of the screw engaging the counterbore of said flange hole to securesaid screw carrying element from separating movement relative to theflange.

3. A sanding drum comprising a pair of segmental pivotally connecteddrum elements adapted when brought together to constitutea circular drumfor receiving an abrasive web, comprising a hub member having a radiallyextending annular flange, means for rigidly securing one of saidelements to the hub member, said flange having a chord-like slot thereinterminating in a counterbored axially extending hole, the other of saidelements having an axially extending hole adapted to be alined with saidfirst named hole when in operative relation to said flange, and a headedscrew carried by the last named element and movable in said slot, theshank of said screw extending through said holes in the operativeposition of the elements and the head of the screw engaging thecounterbore of said flange hole to secure said screw carrying elementfrom separating movement relative to the flange.

4. A sanding drum comprising a pair of segmental pivotally connecteddrum elements adapted when brought together to constitute a circulardrum for receiving an abrasive web, a hub member, means for rigidlysecuring one of said elements to the hub member, said hub member havinga chord-like slot therein terminating in a counterbored axiallyextending hole, the other of said elements having an axially extendinghole adapted to be alined with said first named hole when in operativerelation to said flange, and a headed screw carriedby the last namedelement and movable in said slot, the shank of said screw extendingthrough said holes in the operative position of the elements and thehead of the screw engaging the counterbore of said flange hole to securesaid screw carrying element from separating movement relative to theflange.

5. A sanding drumlassembly comprising means adapted to be attached tothe arbor of a sanding machine and including a segmentalv drum element,and a further segmental drum element pivotally connected to said firstelement, said elements when brought together constituting a circulardrum for receiving an abrasive web, one of said elements being securedin angularly fixed relation to said arbor and provided with a meme herhaving a slot terminating in a counterbored axially extending hole, theother of said elements having an axially extending hole adapted to bealined with said first named hole when in operative position, and aheaded screw carried by the last named element and movable in said slot,the shank of said screw extending through said holes in the operativeposition of the elements and the head of the screw engaging saidcounterbore to secure said screw carrying elements from separatingmovement.

6. A sanding drum assembly comprising means adapted to be attached tothe arbor of a sanding machine and including a segmental drum element,and a further segmental drum element pivotally connected to said firstelement, said elements when brought together constituting a circulardrum for receiving an abrasive web, one of said elements being providedwith a member having a counterbored axially extending hole, the other ofsaid elements having an axially extending hole adapted to be alined withsaid first named hole when in operative position, and a headed screwadapted. to coact with said holes, the shank of said screw extendingthrough said holes in the operative position of the elements and thehead of the screw engaging said counterbore to secure said screwcarrying elements from separating movement, one of said elements beingin angularly fixed relation to said arbor.

'7. An assembly of the type described comprising a pair of segmentaldisk elements having means for pivotally connecting the same at one sidethereof, means fixedly securing one of said elements to the arbor of asanding machine, and means for securing said elements in operativerelation to constitute a drum for receiving a surface finish strip,comprising a member in fixed relation to one of saidelements having achord-like slot opening to the exterior thereof and terminating at itsinner end in a counterbored recess, the other of said elements having ascrew threaded therein and extending therethrough, substantiallyparallel to the axis of the drum, said'screw being shiftable in saidslot in a direction parallel to the length of said axis and providedwith an enlarged conical head engaging in said counterbore when thescrew is tightened with the elements inoperative relation to therebyprevent subsequent separating movement of the elements.

8. An assembly of the type described comprising a pair of segmental diecast disk elements having means for pivotally connecting the same at oneside thereof, hub means cast integral with one of said elements formounting the assembly on the arbor of the sanding machine, and means forsecuring said elements in operative relation to constitute a drum forreceiving a surface finish strip, comprising a projecting member infixed relation to said one of said elements hav a chord-like slotopening to the exterior thereof and terminating at its inner end in acounterbored recess, the other of said elements having a screw threadedtherein and extending therethrough substantially parallel to the axis ofthe drum, said screw being shiftable in said slot in a directionparallel to the length of said axis and provided with an enlargedconical head engaging in said counterbore when the screw istightenedwith the elements in operative relation to thereby prevent subsequentseparating movement of theelements.

9. A drum comprising a flanged hub having a slot extending from theperiphery thereof terminating in acountersunk recess, a pair ofsegmental complementary drum elements each formed of a pair of flangedsheet metal members disposed back to back to provide a rim portion andhaving oppositely struck-out web portions receiving the flange of saidhub, the web portions of one member being fixedly secured to the flangeof the hub, the other member being swingably secured to the fixed memberand adapted to telescopingly engage said hub flange, a clamping elementcarried by the swingable member adapted to enter said slot and having aninwardly tapered head engageable with said recess for clamping theswingable element in its closed position, a web supporting cushionsecured tothe rim of said drum, said rim being provided with angledguard members overlying the ends of the cushion, and web engaging pinscarried by said drum elements adjacent said guards and with which a webdrawn over said guards may be engaged.

10. A drum'comprising a flanged hub having a. slot extending from theperiphery thereof terminating in a countersunk recess, a pair ofsegmental complementary drum elements each formed of a pair of flangedsheet metal members disposed back to back to provide a rim portion andhaving oppositely struck-out web portions receiving the flange of saidhub, the web portions of one member being fixedly secured to the flangeof the hub, the other member being swingably' secured to the fixedmember and adapted to telescopingly engage said hub flange, a clampingelement carried by the swingable member adapted to enter said slot andhaving an inwardly tapered head engageable with said recess for clampingthe swingable element in its closed position, and a websupportingcushion secured to the rim of said drum.

11. A drum comprising a flanged hub, a pair of segmental complementarydrum elements each formed of a pair of flanged sheet metal membersdisposed back to'back to provide a rim portion and having oppositelystruck-out web portions receiving the flange of said hub, the webportions of one member being fixedly secured to the flange of the hub,the other member being swingably' secured to the fixed member andadapted to telescopingly engage said hub flange, means for detachablysecuring said swingable member to said hub flange, a web supportingcushion secured to the rim of said drum, said rim being provided withguard elements overlying the ends of the cushion, and web engaging pinscarried by said drum elements adjacent said guards and with which a webdrawn over said guards may be engaged.

12. A drum assembly of the type described adapted for ready positioningand securing on the arbor of an actuating machine and for ready removaland replacement of a surface finishing web thereon, comprising a hubmember adapted to be positioned on said arbor and to abut a shoulder onthe latter, a pair of coacting drum elements pivotally connectedtogethensaid drum elements each being made up of a pair of flanged sheetmetal members disposed back to back and secured together to provide arim portion and having oppositely struck-out web portions providinganinternal semi-circular annular channel, said hub member having aradially extending annular flange receivable in the channels of saidelements, means for fixedly securing said flange 'in one of saidchannels, and means for locking the elements in operative coactingrelation with the other channel receiving said hub flange, comprising alocking ring threadedly engaging said hub and having an inner taperedbinding surface, said elements having out-turned lips at the inner edgesof the channels receivable in said locking ring and engageable by saidbinding portion to restrain the elements from separation.

13. A drum assembly of the type described adapted for ready positioningand securing on the arbor of an actuating machine and for ready removaland replacement of a surface finishing web thereon, comprising a hubmember adapted to be positioned on said arbor and to abut a shoulder onthe latter, a pair of coacting drum elements pivotally connectedtogether and each of which has an internal semi-circular annularchannel, said hub member having a radially extending annular flangereceivable in the channels of said elements, means for fixedly securingsaid flange in one of said channels, and means for locking the elementsin operative coacting relation with the other channel receiving said hubflange, comprising a locking ring threadedly engaging said hub andhaving an inner tapered binding surface, said elements having out-turnedlipsat the inner edges of the channels receivable in said locking ringand engageable by said binding portion to restrain the elements fromseparation. 4

14. A drum assembly of the type described adapted for ready positioningand securing on the arbor of an actuating machine and for ready removaland replacement of a surface finishing web thereon, comprising a hubmember adapted to be positioned on said arbor and to abut a shoulder onthe latter, a pair of coacting drum elements pivotally connectedtogether, said drum elements each being made up of a pair of flangedsheet metal members disposed back to back and secured together toprovide a rim portion and having oppositely struck-out Web portionsproviding an internal semi-circular annular channel, said hub memberhaving a radially extending annular flange receivable in the channels ofsaid elements, means for fixedly securing, said flange in one of saidchannels, and means for locking the elements in operative coactingrelation with the other channel receiving said hub flange.

15. A sanding drum assembly adapted for ready positioning and securingon the arbor of a sanding machine and for ready removal and replacementof an abrasive Web thereon, comprising a hub member adapted to bepositioned on said arbor, a pair of coacting drum elements pivotallyconnected together and each of which has an internal semi-circularannular channel provided with out-turned lips, said hub member having aradially extending annular flange receivable in the channels of saidelements, means for fixedly securing said flange in one of saidchannels, and means for locking the elements in operative coactingrelation with the other channel of said movable element receiving saidhub flange, comprising a locking ring adapted to be mounted on the arborand having an inner tapered binding surface engageable with said lips,and means for axially unging said. ring for binding engagement of saidsurface With said lips. WILLIAM H VAN ZOMEREN.

